Publication Date:
1991-05-17
Description:
Some strains of Escherichia coli contain retroelements (retrons) that encode genes for reverse transcriptase and branched, multicopy, single-stranded DNA (msDNA) linked to RNA. However, the origin of retrons is unknown. A P4-like cryptic prophage was found that contains a retroelement (retron Ec73) for msDNA-Ec73 in an E. coli clinical strain. The entire genome of this prophage, named phi R73, is 12.7 kilobase pairs and is flanked by 29-base pair direct repeats derived from the 3' end of the selenocystyl transfer RNA gene (selC). P2 bacteriophage caused excision of the phi R73 prophage and acted as a helper to package phi R73 DNA into an infectious virion. The newly formed phi R73 closely resembled P4 as a virion and in its lytic growth. Retronphage phi R73 lysogenized a new host strain, reintegrating its genome into the selC gene of the host chromosome and enabling the newly formed lysogens to produce msDNA-Ec73. Hence, retron Ec73 can be transferred intercellularly as part of the genome of a helper-dependent retronphage.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Inouye, S -- Sunshine, M G -- Six, E W -- Inouye, M -- AI04043/AI/NIAID NIH HHS/ -- GM44012/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 May 17;252(5008):969-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey at Rutgers, Piscataway 08854.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1709758" target="_blank"〉PubMed〈/a〉
Keywords:
Base Sequence
;
Blotting, Southern
;
Chromosome Mapping
;
Coliphages/*genetics/ultrastructure
;
DNA, Bacterial/genetics
;
DNA, Viral/genetics
;
Escherichia coli/*genetics
;
*Genes, Bacterial
;
*Genes, Viral
;
Microscopy, Electron
;
Molecular Sequence Data
;
Nucleic Acid Hybridization
;
Oligonucleotide Probes
;
Open Reading Frames
;
RNA, Transfer/*genetics
;
RNA-Directed DNA Polymerase/genetics
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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